The present invention relates to hydraulically operated drilling apparatus and the like and in particular to an arrangement of such apparatus in a portable mast or vertical standard.
Portable hydraulically operated drilling apparatus on which the rotary drilling head or capstan is mounted is known. Drilling rods, held by the capstan, extend downwardly though a slip or guide device in a direction parallel to the mast. The drill-head is operated by a rope winch mounted on the upper end of the mast or on an extension thereof and is moveable along the length of the mast by a cable and pulley system activated by a hydraulic motor.
The mast must be of such a form that it has sufficient rigidity and resistance to bending and twisting so as to accurately carry the drilling head. However, it must be without excessive weight since a light weight mast is important for portable apparatus, intended to be mounted upon standard vehicles or trucks. In addition, the mast must be of such construction that the individual parts arranged and mounted on it can be easily reached in order to be repaired and serviced.
Various embodiments of the formation of the mast have been known. In one instance, the mast is formed as a lattice, or open frame work rig, the rigidity of which is insured by using slant bracings and cross bracings. With this open type rig the parts can be easily serviced. In another embodiment the mast may be made from identically profiled steel beams, as for instance when a pair of double-T-profile beams (H beams) are arranged in parallel spaced position opposite each other and are welded together with the plurality of cross plates. The edges of the beams in this arrangement which lie on a common plane can thus form the outer rail for the drill head as well as the means for attaching the slip or guide device. However, in this form, the ability to serve and clean the parts of the apparatus which are arranged within the beam construction is extremely difficult because of the narrow space between the members.
In any event, whether the mast is formed of a lattice type rig, or a welded box-like frame, a great many manufacturing steps are required to form the mast. It is therefore expensive to provide the masts of the prior art. Furthermore, the numerous bracings and other constructional materials render the masts extremely heavy. Still further, when the mast is formed of steel rails, for instance the two double-T beams or even from a pair of oppositely oriented U-beams, masts of very large dimensions are obtained increasing the weight and requiring considerably complex mechanisms for mounting the same upon the vehicles.
It is the object of the present invention to provide a hydraulically actuated drilling apparatus which overcomes the disadvantages and difficulties of the prior art.
It is a further purpose of the present invention to provide a mast for hydraulically operated drilling apparatus which is simpler and cheaper to manufacture and which has an extraordinarily low weight and a particularly high resistance to buckling or bending in addition to a strong resistance against turning moments.
It is another object of the present invention to provide a hydraulically actuated drill having an improved mast in which substantially all the operating parts may be housed and yet provides ample room and ability for repair and servicing.
The foregoing objects, other objects, together with the numerous advantages of the present invention will be apparent from the following disclosure.